Theses - Dept. of Mechanical Engineeringhttp://hdl.handle.net/1721.1/7605
Thu, 08 Dec 2016 18:31:56 GMT2016-12-08T18:31:56ZDesign, development, and fabrication of a vibration detecting robotic foot-pad using embedded PVDF stripshttp://hdl.handle.net/1721.1/105720
Design, development, and fabrication of a vibration detecting robotic foot-pad using embedded PVDF strips
Abdolrahim Poorheravi, Negin
This thesis shows the design, fabrication, and early characterization process of a slip-sensing foot-pad made from PVDF strips embedded in a rubber molded structure. What follows suggests a proof-of-concept for a design that can be used to detect vibrations on the edges of a teethed structure. The ability to detect localized vibrations in the embedded PVDF sensors in this foot-pad can be used in future studies to measure the contact-patch area and investigate the relationship between the change in such area and incipient slip. The future iterations of the proposed foot-pad can be used to integrate with current foot-pads worn by legged robots such as MIT Cheetah to enable them to predict slippage. An experimental procedure was used to find the effect of a localized stress on the embedded sensors' data. Three iterations of the foot-pad were designed and fabricated. Furthermore, a custom slippage tester was designed and built for future studies. The experimental results suggested that the effect of triggering on the foot-pad was highly localized since it did not affect neighboring sensors. This behavior can be used to measure changes in the contact-patch area since loss of contact between the ground and foot-pad introduces vibrations on the edges of the pad. Though further data collection and mapping should be conducted for this foot-pad to be able to predict slippage, the experimental results suggest that usage of urethane embedded PVDF sensors can be a viable and promising approach in achieving this goal by detecting the localized vibrations induced by the slip incident.
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.; Cataloged from PDF version of thesis.; Includes bibliographical references (page 31).
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/1721.1/1057202016-01-01T00:00:00ZIntroduction to kinetic sculpture : a one-week course for middle school studentshttp://hdl.handle.net/1721.1/105719
Introduction to kinetic sculpture : a one-week course for middle school students
Suresh, Martin R. (Martin Ravindra)
A one-week course in kinetic sculpture was designed to introduce middle school students to the marriage of art and engineering. Because art can appeal to different sensibilities than engineering alone, it can serve as a means to broaden perspectives of students with different motivations. In light of increasing emphasis on the development of programs in STEM (Science, Technology, Engineering, and Math) in U.S. education, this project fills a need for more opportunities in STEAM (Science, Technology, Engineering, Arts, and Math). Even though the availability and popularity of STEAM programs for children is growing, these opportunities for young children are still limited. Therefore, there is a market for a course that incorporates art and the engineering design process like this one. Daily activities in an introductory week-long kinetic sculpture course are defined. Each day's lessons are provided along with resources for further study. The structure of the course is based on sound pedagogical practice. The strength of the course is its ability to incorporate science and art in a fun way that will be appealing to students. Future work would consist of the expansion of the lessons with more detail for teachers and the addition of more alternate activities.
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 49-50).
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/1721.1/1057192015-01-01T00:00:00ZImproving the concentrated solar power plant through connecting the modular parabolic solar troughhttp://hdl.handle.net/1721.1/105718
Improving the concentrated solar power plant through connecting the modular parabolic solar trough
Abiose, Kabir
Concentrating solar power (CSP) stands as a promising renewable energy technology with the ability to contribute towards global reduction of carbon emissions. A major obstacle to increased adoption of CSP plants has to do with their high initial investment cost; consequently, there is a powerful desire to find improvements that decrease the initial capital investment for a CSP plant. One such improvement involves connecting modularized parabolic trough segments, each with the same dimensions, decreasing the overall amount of actuators required along with greatly simplifying system control architecture. This thesis is concerned with the extent to which parabolic solar trough modules can be connected together while still being able to operate to desired accuracy under expected load. Accuracy requirements are calculated, along with expected loads resulting in frictional torque on the trough. These expected loads are combined with a model for the effect of connecting multiple trough modules to generate a relationship between number of chained modules and required torsional stiffness. To verify said model, an experimental setup was designed and constructed to simulate loads due to both trough weight and wind loads.
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.; Cataloged from PDF version of thesis.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/1721.1/1057182016-01-01T00:00:00ZCharacterization of synchronizer performance for a clutchless transmissionhttp://hdl.handle.net/1721.1/105717
Characterization of synchronizer performance for a clutchless transmission
Antonini, Amado
Synchronizers are a ubiquitous component of almost every type of transmission in modem vehicles. They are mechanical devices whose function is to ensure that components rotating at different rates can be harmonized smoothly and without eroding their surfaces. They are responsible for both the durability of the transmission and the comfort of the passengers. This work analyzes the capabilities and limitations of synchronizers to be used in a novel transmission. It is a contribution to a larger project whose goal is to develop a hybrid, clutchless transmission for a performance vehicle that will improve efficiency by eliminating the friction and mechanical losses inherent in a traditional clutch. An overview of the synchronization process is presented followed by a simplified mathematical model of the common baulk-ring synchronizer. The model is experimentally validated in order to make predictions of the device's performance on the new transmission. Several simulated scenarios are then developed that provide information that is critical for designing synchronizers for the clutchless transmission. Matlab code was developed for these simulations and is provided at the end for replication of the results. Considering the demanding environment under which the synchronizers are expected to operate in the clutchless transmission, the possible failure modes of the synchronizer components are investigated. Finite element analysis (FEA) is used to predict the maximum loads on the synchronizer ring before the material yields. An energy analysis is also performed to ensure that the energy dissipation rate of the friction surfaces is adequate.
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.; Cataloged from PDF version of thesis.; Includes bibliographical references (pages 50-51).
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/1721.1/1057172016-01-01T00:00:00Z